1. Field
The disclosure relates to an anti-lock brake system. More particularly, the disclosure relates to a plunger of a low pressure accumulator.
2. Description of the Related Art
In general, an anti-lock brake system is installed in a vehicle to prevent wheels from slipping by intermittently controlling braking force applied to the wheels for the purpose of safe braking of the vehicle.
Such a brake system includes a master cylinder to generate braking pressure by receiving braking force, which is derived from the operation of a brake pedal and amplified by a booster, a solenoid valve to control the braking pressure transferred to hydraulic brakes provided at front and rear wheels, an accumulator to attenuate the pressure pulsation of oil, and a pump operated by a motor. The above elements are arranged along a hydraulic line.
Meanwhile, the solenoid valve is installed in the hydraulic line of each hydraulic brake to control the braking pressure generated from the master cylinder and a low pressure accumulator is installed below the solenoid valve to temporarily store oil discharged from the hydraulic brake in the pressure reduction mode. In addition, the pump is installed in the vicinity of an exhaust port of the low pressure accumulator to compress low pressure oil and to pump the compressed low pressure oil to a high pressure accumulator. The oil exhausted from the high pressure accumulator is circulated to the master cylinder or the solenoid valve.
Among the above components of the anti-lock brake system, the low pressure accumulator temporarily stores oil discharged from each brake during the pressure reduction process of the braking pressure in order to attenuate the pressure pulsation.
The low pressure accumulator includes a cylinder, a piston for keeping the interior of the cylinder in the air-tight state, a spring for elastically supporting the piston and a plug for opening/closing the cylinder while supporting the spring.
In addition, a vent seal and a vent cap are assembled with the plug in order to remove the pressure, which is generated in the cylinder due to the compression and expansion of air in the cylinder.
However, according to the related art, time and equipment are required to assemble the vent seal and the vent cap with the plug, so that the manufacturing cost may be increased.